STYLET, SYSTEM INCLUDING A STYLET, AND METHODS FOR PERFORMING A MEDICAL PROCEDURE USING A STYLET - Patent application

Abstract

The medical device system includes a radiofrequency generator, a stylet, and an introducer. The stylet includes an elongated shaft having a proximal shaft portion and a distal shaft portion defining a distal end. The shaft is rigid. A radiofrequency puncture electrode is at the distal end of the shaft. The radiofrequency puncture electrode is electrically connectable to the radiofrequency generator. The introducer includes an elongated tube extending between a proximal tube portion and a distal tube portion defining the distal end. The shaft is receivable within the tube with the electrode protruding from the distal end.

Description

[Technical field]

[0001] This specification relates to medical devices, and more particularly to medical devices such as stylets, systems including such stylets, and methods for using such stylets. [Background technology]

[0002] There remains a need in the art for improved stylets. Summary of the Invention

[0003] The following summary is intended to introduce the reader to various aspects of the detailed description, but it is not intended to define or limit any of the invention. A stylet is disclosed. According to some aspects, the stylet includes an elongate shaft having a proximal portion and a distal portion. The shaft is rigid. The distal portion defines a blunt distal end. A radiofrequency (RF) puncture electrode is at the distal end. The radiofrequency puncture electrode is electrically connectable to a radiofrequency generator.

[0004] In some embodiments, the shaft includes a metal body and an electrically insulating material on the metal body. The radiofrequency puncture electrode can be the electrically exposed tip of the metal body or a metal piece bonded to the metal body.

[0005] In some embodiments, the stylet further includes a hub joined to the proximal portion of the shaft, the hub can be configured to electrically connect the metal body to a radio frequency generator for delivering radio frequency energy along the metal body from the proximal portion of the shaft to the radio frequency puncture electrode.

[0006] In some embodiments, the metal body includes a lumen extending therethrough from the proximal portion to the distal portion. The distal portion may include one or more ports in fluid communication with the lumen.

[0007] In some embodiments, the stylet further includes a lock attached to the proximal portion for securing the stylet to the introducer. A system of medical devices is also disclosed. According to some aspects, the system of medical devices includes a radio frequency generator, a stylet, and an introducer. The stylet includes an elongated shaft having a shaft proximal portion and a shaft distal portion defining a shaft distal end. The shaft is rigid. A radio frequency puncture electrode is at the shaft distal end. The radio frequency puncture electrode is electrically connectable to the radio frequency generator. The introducer includes an elongated tube extending between a tube proximal portion and a tube distal portion defining the tube distal end. The shaft is receivable within the tube with an electrode protruding from the tube distal end.

[0008] In some embodiments, the shaft distal end is blunt. In some embodiments, the stylet can be locked onto the introducer with the shaft received within the tube and the electrodes protruding from the distal end of the tube.

[0009] In some embodiments, the shaft comprises a metallic body and the tube comprises an electrically insulating material. In some embodiments, the proximal tube portion has a first diameter and the distal tip of the distal tube portion has a second diameter that is smaller than the first diameter.

[0010] Also disclosed is a method for performing a medical procedure. According to some aspects, the method for performing a medical procedure includes: a. percutaneously advancing a stylet and an introducer toward a patient's heart with the stylet received within the introducer; and b. delivering radio frequency energy from an electrode of the stylet to pierce tissue blocking the path of the stylet and introducer.

[0011] In some embodiments, the tissue is a fibrous tissue. In some embodiments, the method further includes contacting the heart with an electrode and delivering radio frequency energy from the electrode to puncture the pericardium of the heart. The method may further include advancing a distal end of the stylet and a distal end of the introducer through the puncture. The method may further include retracting the stylet from the introducer.

[0012] In some embodiments, the method further includes contacting the heart with the electrode, withdrawing the stylet from the introducer, advancing a secondary radiofrequency puncture device through the introducer toward the heart, and delivering radiofrequency energy from the secondary radiofrequency puncture device to puncture the pericardium of the heart.

[0013] In some embodiments, in step a., the stylet is locked to the introducer. In some embodiments, the method includes delivering a contrast agent through the stylet from a port in the stylet.

[0014] The accompanying drawings are intended to illustrate, but not to limit, the articles, methods, and apparatus of the present disclosure. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a perspective view of a system of medical devices in an assembled state. [Diagram 2] FIG. 2 is a perspective view of the system of FIG. 1 in an unassembled state. [Diagram 3] 3 is a cross-section taken along line 3-3 of FIG. 1. [Figure 4] 1 is a schematic diagram of method steps for performing a medical procedure. [Diagram 5] FIG. 5 is a schematic diagram showing the steps following those of FIG. 4. [Figure 6]FIG. 6 is a schematic diagram showing the steps following those of FIG. 5. [Figure 7] FIG. 7 is a schematic diagram showing the steps following those of FIG. 6. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Various devices, processes, or configurations are described below to provide examples of embodiments of the claimed subject matter. The examples described below do not limit any claim, and any claim may encompass a process, device, or configuration different from those described below. The claims are not limited to a device, process, or configuration having all of the features of any one device, process, or configuration described below, or to features common to more than one or all of the devices, processes, or configurations described below. The devices, processes, or configurations described below may not be embodiments of any of the exclusive rights conferred by the issuance of this patent application. Any of the subject matter described below to which no exclusive rights are conferred by the issuance of this patent application may be the subject of another protected document, e.g., a continuing patent application, and the applicant, inventor, or patentee does not intend to abandon, abandon, or release to the public any such subject matter by its disclosure herein.

[0017] Generally disclosed herein is a stylet that can be used in various medical procedures, such as a pericardiocentesis procedure. The stylet is configured to deliver radio frequency (RF) energy to tissue to puncture the tissue. This can facilitate passage through the body to access body cavities as well as target tissue sites. For example, the stylet can be advanced percutaneously toward a target location within a patient's body, such as the heart. If progression to the target location is difficult due to the presence of impassable tissue (e.g., fibrous tissue) in the path of the stylet, RF energy can be delivered from the stylet to puncture the tissue. Furthermore, once the target location is reached, the stylet can be optionally used to puncture the target location by delivery of RF energy.

[0018] 1 and 2, a medical device system 100 is shown. The system 100 generally includes an RF generator 102, a stylet 104 electrically connectable to the RF generator 102, and an introducer 106 within which the stylet 104 can be received. In FIG. 1, the stylet 104 is received within the introducer 106, and in FIG. 2, the stylet 104 has been removed from the introducer 106.

[0019] The RF generator 102 may be any suitable RF generator, such as the RF generator sold under the trade name RFP-100A RF Puncture Generator by Baylis Medical Company (Montreal, Canada), and will not be described in detail herein.

[0020] 2 and 3, the stylet 104 generally includes an elongated, rigid (i.e., does not bend or flex significantly during normal use) shaft 108. The shaft 108 has a proximal portion 110 (also referred to herein as the "proximal shaft portion") that defines a proximal end (not shown, also referred to herein as the "proximal shaft end") and a distal portion 112 (also referred to herein as the "distal shaft portion") that defines a distal end 114 (also referred to herein as the "distal shaft end"). The distal end 114 is blunt to avoid or minimize puncturing tissue by mechanical force alone.

[0021] 2 and 3, an RF puncture electrode 116 is at the distal end 114 of the shaft 108 and is electrically connectable to the RF generator 102 (not shown in FIG. 3). In the illustrated embodiment, the shaft 108 includes a metal body 118 (not visible in FIG. 2) and an electrically insulating material 120 on the metal body 118 for electrically connecting the electrode 116 to the RF generator 102. For example, the metal body 118 can be a stainless steel cannula, the electrically insulating material 120 can be high density polyethylene, and the electrode 116 can be a metal piece joined (e.g., by soldering or welding) to the metal body. In the illustrated embodiment, the stylet 104 further includes a hub 122 joined to the proximal portion 110 of the shaft 108, the hub 122 configured to electrically connect the metal body 118 to the RF generator 102. For example, the hub 122 can electrically connect the metal body to a cable 124 (shown in FIG. 2), which can be connected to the RF generator 102. Thus, RF energy can be delivered from the RF generator 102 to the cable 124, from the cable 124 to the metal body 118, and from the metal body 118 to the electrode 116, which delivers the RF energy to tissue to pierce the tissue.

[0022] In an alternative embodiment (not shown), the shaft may include a separate electrical connector for connecting the electrode to an RF generator, for example, wires for connecting to the RF generator may extend from the electrode through the shaft.

[0023] In alternative embodiments (not shown), the electrodes may be of other configurations, for example the electrodes may be the electrically exposed tips of metal bodies. 3, in the illustrated embodiment, the metal body 118 includes a lumen 126 extending therethrough from the proximal portion 110 to the distal portion 112. The distal portion 112 further includes a fluid port 128 (only one of the fluid ports is labeled) in fluid communication with the lumen 126 for delivering fluid from the proximal portion 110 to the distal portion 112 through the lumen 126 and out of the lumen 126 via the fluid port 128. As described below, the fluid delivered through the fluid port 128 may be a contrast agent. In the illustrated embodiment, the distal portion 112 includes two fluid ports. In alternative embodiments, another number of fluid ports (i.e., one or more fluid ports) may be provided.

[0024] 2 and 3, the introducer 106 generally includes a tube 130 that is elongated. The tube 130 has a proximal portion 132 (also referred to herein as the "tube proximal portion") that defines a proximal end 134 (shown in FIG. 3 and also referred to herein as the "tube proximal end") and a distal portion 136 (also referred to herein as the "tube distal portion") that defines a distal end 138 (also referred to herein as the "tube distal end"). The distal end 138 of the tube 130 is blunt to avoid or minimize puncturing or damaging tissue.

[0025] 3, in the illustrated embodiment, the tube 130 includes an outer layer 140 of a relatively soft polymeric material (e.g., high density polyethylene) and an inner reinforcement layer 142 (e.g., a layer of stainless steel) within the outer layer 140. In the illustrated embodiment, the inner layer 142 extends short of the distal end 138 of the tube, leaving the distal tip 144 of the tube 130 unreinforced. This minimizes the risk of tissue damage resulting from contact with the introducer 106. Additionally, the distal tip 144 has a reduced diameter compared to the proximal portion 132 of the tube 130 (i.e., the proximal portion 132 has a first diameter and the distal tip 144 has a second diameter that is smaller than the first diameter). As described below, this can facilitate insertion of the distal tip 144 through the puncture. The distal tip 144 can have a length of, for example, about 1 cm to about 4 cm. In an alternative embodiment, the entire distal tip may be tapered.

[0026] 2 and 3, in the illustrated embodiment, the introducer 106 further includes a hub 146 that is joined to the proximal portion 132 of the tube 130. Optionally, tube 130 may include a lubricious coating (not shown) to facilitate advancement.

[0027] 3, the shaft 108 of the stylet 104 can be received within the tube 130 of the introducer 106. More specifically, as shown in FIG. 3, the shaft 108 of the stylet 104 can be received within the tube 130 of the introducer 106 with the electrodes 116 protruding from the tube distal end 138 and the fluid port 128 protruding from the tube distal end 138. Moreover, the stylet 104 and introducer 106 can be locked together in the position shown in FIG. 3. More specifically, the hub 122 of the stylet 104 can be locked to the hub 146 of the introducer 106. This locking can be accomplished, for example, by a threaded luer lock type mechanism.

[0028] In the illustrated embodiment, as described above, the stylet 104 includes an electrically insulating material 120. In an alternative embodiment (not shown), the stylet's electrically insulating material may be omitted and the introducer tube may act as the electrically insulating material for the stylet.

[0029] In any of the above embodiments, the stylet and / or introducer may include one or more radiopaque markers to facilitate visualization under fluoroscopy. 4-7, a method for performing a medical procedure, and more specifically, a method for pericardiocentesis, will be described. The method will be described with reference to system 100 of FIGS. 1-3. However, the method is not limited to system 100, and system 100 is not limited to operating in accordance with the described manner.

[0030] 4, with the stylet 104 received and locked within the introducer 106 and the electrode 116 protruding from the tube distal end 138, the stylet 104 and introducer 106 may be advanced percutaneously toward the patient's heart 400. For example, the stylet 104 and introducer 106 may be advanced via a subxiphoid approach. Mechanical force may be used initially to advance the stylet 104 and introducer 106. Still referring to FIG. 4, if tissue 402 (e.g., fibrous tissue) blocks the path of the stylet 104 and introducer 106, thereby requiring excessive mechanical force to pass through the tissue 402, RF energy may be delivered from the electrode 116 to pierce the tissue 402. This avoids the use of excessive mechanical force.

[0031] Once the tissue 402 has been punctured, the delivery of RF energy can be stopped (either automatically at the end of a set pulse or manually) and mechanical force can be reapplied to continue advancing the stylet 104 and introducer 106 towards the heart 400. The stylet 104 and introducer 106 can be advanced until the electrode 116 contacts the pericardium 404 of the heart 400, as shown in FIGURE 5. Optionally, contrast agent can be delivered through the stylet 104 from a fluid port 128 (not numbered in FIGS. 4-7) while viewing the stylet 104 and introducer 106 under fluoroscopy to confirm the position of the stylet 104 and introducer 106.

[0032] With the position of the stylet 104 and introducer 106 confirmed and the electrode 116 in contact with the pericardium 404, RF energy can be delivered by the RF generator 102 (not shown in FIGS. 4-7) from the electrode 116 to puncture the pericardium 404. The shaft distal end 114 and tube distal end 138 can then be advanced through the puncture and into the pericardial space 406, as shown in FIG. 6. Optionally, to again confirm the position of the stylet 104 and introducer 106, contrast can be delivered through the stylet 104 and out of the fluid port while viewing the stylet and introducer under fluoroscopy.

[0033] 7, the stylet 104 (not visible in FIG. 7) may then be retracted from the introducer 106, leaving the distal end 138 in place within the pericardial space 106. A secondary medical device (e.g., a guidewire, not shown) may then be advanced through the introducer 106 for use in a subsequent step of the medical procedure.

[0034] In an alternative embodiment (not shown), rather than using the stylet 104 to puncture the pericardium 404, a secondary RF puncture device (not shown) can be used to puncture the pericardium (i.e., the stylet can be used to facilitate advancement towards the heart rather than to puncture the pericardium). For example, once the stylet and introducer reach the heart (as shown in FIG. 5) and the electrodes are in contact with the heart, the stylet can be withdrawn from the introducer. A secondary RF puncture device (e.g., an RF guidewire) can be advanced through the introducer towards the heart, and RF energy can be delivered from the secondary RF puncture device to puncture the pericardium.

[0035] Although the above description provides examples of one or more processes, devices, or configurations, it will be understood that other processes, devices, or configurations may be within the scope of the following claims.

[0036] To the extent that any amendments, characterizations, or other assertions previously made (in this patent, or in any related patent application or patent, including any parent, sibling, or progeny) with respect to any prior art or other art may be construed as a disclaimer of any subject matter supported by the present disclosure of this application, applicant hereby cancels and revokes such disclaimer. Applicants also respectfully suggest that it may be necessary to reconsider any prior art previously discussed in any related patent application or patent, including any parent, sibling, or progeny.

Claims

1. a stylet including an elongate shaft having a hub joined to a proximal portion and a distal portion, said shaft being rigid and said distal portion defining a blunt distal tip; a radio frequency puncture electrode at the distal end of the shaft, the radio frequency puncture electrode being electrically connectable to a radio frequency generator; an introducer comprising an elongated tube extending between a proximal tube portion having a first diameter and a distal tip having a second diameter smaller than the first diameter, the proximal tube portion comprising an outer layer of polymeric material and an inner reinforcing layer, the inner reinforcing layer extending short of the distal tip to minimize risk of tissue damage due to contact with the introducer, the shaft being receivable within the elongated tube with the radiofrequency puncture electrode protruding from the distal tip, and the shaft being retractable from the elongated tube; A system comprising:

2. The system of claim 1 , wherein the shaft comprises a metal body and an electrically insulating material on the metal body.

3. The system of claim 2 , wherein the radiofrequency puncture electrode comprises an electrically exposed tip of the metal body.

4. The system of claim 2 , wherein the radiofrequency puncture electrode comprises a metal strip joined to the metal body.

5. A system as described in any one of claims 2 to 4, wherein the hub is configured to electrically connect the metal body to the radio frequency generator to deliver radio frequency energy along the metal body from the proximal portion of the shaft to the radio frequency puncture electrode.

6. 6. The system of claim 2, wherein the metal body includes a lumen extending therethrough from the proximal portion to the distal portion, the distal portion including one or more ports in fluid communication with the lumen.

7. The system of claim 1 , further comprising a lock attached to the proximal portion for securing the stylet to the introducer.

8. The system of claim 7 , wherein the lock comprises a luer lock.

9. 9. The system of claim 7 or 8, wherein the elongated tube includes a lubricious coating.

10. The system of claim 6 , wherein the stylet is lockable to the introducer with the shaft received within the tube and the electrode and the one or more ports protruding from a distal end of the tube.

11. The system of claim 1 , wherein the outer layer extends to a location distal to the inner reinforcement layer.

12. The system of any one of claims 1 to 11, further comprising a radio frequency generator.

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